Rosanov J. M. RussiaSt. PetersburgInstitute of Cytology, Russian Academy of Sciences, 4 Tikhoretsky pr., St. Petersburg 194064, Russiarozanov@mail.cytspb.rssi.ru Author's articles DISTRIBUTION OF THE «EASTERN» AND «WESTERN» FORMS OF THE MARSH FROG, PELOPHYLAX RIDIBUNDUS, AND THEIR PARTICIPATION IN THE ORIGIN OF HEMICLONAL HYBRIDS, P. ESCULENTUS IN MARI EL REPUBLIC